Fluid composition



Patented May 29, 1934 UNITED STATES PATENT OFFICE FLUID comosrrron No Drawing. ApplicationJune 29, 1932, Serial No. 619,994

4 Claims. (Cl. 252-5) Our invention relates to a fluid composition suitable for use in fluid pressure devices and systems such as shock absorbers, hydraulic jacks, and hydraulic actuating apparatus for vehicle 5 brakes. To be applicable for use as a power transmitting means in hydraulic brakes, a fluid should have quite a number of special characteristics. It should not solidify at the lowest atmospheric temperatures occurring in any locality where motor vehicles are used, nor vaporize unless at temperatures much higher than atmospheric. It must be viscous at all temperatures within the range just mentioned, and its viscosity must not be too high at minimum temperatures to prevent its flow under relatively .low pressure. It should be without chemical or physical effect on rubber and not contain or develop, during the Parts by volume Castor oil Ethyl ester of ortho toluene sulfonamid 18 Ethyl ester of para toluene sulfonamid 18 36 Mono ethyl ether of glycerine 24 while the proportions may vary considerably,

those above given are found to be quite'satisfaotory.

40 While the toluene sulfonamid ester content of the composition may be entirely of a single ester, the composition given is to be preferred, not only since the solidifying point of the mixture is lower but since the cost is less due to the fact that in the manufacture of toluene sulfonarnids the ortho and para isomers are formed in about equal proportions and the expense of separating the isomers can be saved by using the ethyl ester of the mixture.

-While a fluid comprising chiefly castor oil and mono ethyl ether of glycerin'e, in proportions of approximately 60 parts of the former to 40 parts of the latter, would constitute a fluid having most of the desired characteristics, it would be some- 5 what hygroscopic and it is, therefore, desirable to also employ a non-hygroscopic fluid element having higher boiling point than the ether of gly cerine, which fluid must, of course, also be substantially inert toward rubber and metals. We have found that a toluene sulfonamid ester complies with these requirements and that the preferred mixture hereinabove described is nonhygroscopic.

Having fully described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. An operating fluid for fluid pressure apparatus comprising a toluene sulfonamid ester, castor oil, and an alkyl ether of glycerine.

2. An operating fluid for fluid pressure apparatus comprising a toluene sulfonamid ester, castoroil, and mono ethyl ether of glycerine.

3. An operating fluid for fluid pressure apparatus comprising castor oil in approximately 40 parts by volume, ethyl ester of ortho toluene sulfonamid in approximately 18 parts by volume, ethyl ester of para toluene sulfonamid in approximately 18 parts by volume, and mono ethyl ether of glycerine in approximately 24 parts by volume. 90.

4. An operating fluid for fluid pressure apparatus comprising castor oil, mono ethyl ether of glycerine, and a non-hygroscopic fluid having relatively high boiling point and substantially inert to rubber and metals.

JULES BEBIE. v GEORGE L. DOELLINC}. 

